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Biomedical subjects

L Cortés

Publications and source records attributed to L Cortés.

17 recordsLinked to original sources
PubMed2004

Gastric actinomycosis: a rare complication after gastric bypass for morbid obesity.

A 41-year-old woman in November 2002 underwent a gastric bypass by the Capella technique for morbid obesity. Almost 1 year after the surgery, she developed severe vomiting. Radiological studies confirmed a severe stenosis of the gastrojejunal anastomosis. Two pneumatic dilatations of the stenosis failed. In February 2004, she underwent resection of the stenotic anastomosis. Histology showed an intact mucosa and beneath it an abscess filled with numerous filamentous microorganisms, with typical features of Actinomyces. With the diagnosis of gastric actinomycosis, she received a postoperative course of antibiotherapy with imipenem and was discharged after an uneventful recovery. Gastric actinomycosis is a rare infection, of which only 19 additional cases have been reported in the literature. To our knowledge, this is the first case to affect a patient following batriatric surgery. The reported cases of this entity are reviewed, and the diagnostic criteria that could avoid surgery in these cases are discussed.

Actinomycosis↗
PubMed2003

Multicentre surveillance of antimicrobial resistance in enterococci and staphylococci from Colombian hospitals, 2001-2002.

Invasive isolates of staphylococci and enterococci were collected from 15 tertiary care centres in five Colombian cities from 2001 to 2002. A total of 597 isolates were available for analysis. Identification was confirmed by both automated methods and multiplex PCR assays in a central laboratory. Staphylococcus aureus and coagulase-negative staphylococci (CoNS) corresponded to 49.6% and 29.6% of isolates, respectively, and 20.8% were identified as enterococci. MICs of ampicillin, ciprofloxacin, chloramphenicol, erythromycin, gentamicin, linezolid, oxacillin, rifampicin, teicoplanin, tetracycline, trimethoprim/sulfamethoxazole (SXT) and vancomycin were determined using an agar dilution method as appropriate. Screening for vancomycin-resistant S. aureus was also carried out on brain-heart infusion agar plates supplemented with vancomycin. The presence of mecA and van genes was investigated in methicillin-resistant staphylococci and glycopeptide-resistant enterococci (GRE), respectively. All staphylococci were susceptible to vancomycin, teicoplanin and linezolid. No VISA isolates were found. In S. aureus and CoNS, the lowest rates of resistance were found for SXT (7.4%) and chloramphenicol (10.7%), respectively. Resistance to oxacillin in S. aureus and CoNS was 52% and 73%, respectively. The mecA gene was detected in 97.5% of methicillin-resistant S. aureus isolates. In enterococci, resistance to glycopeptides was 9.7%: vanA (58.3%) and vanB (41.7%) genes were found. Pulsed-field gel electrophoresis indicated that the GRE isolates were closely related. Rates of resistance to ampicillin, ciprofloxacin, chloramphenicol, rifampicin and high levels of gentamicin and streptomycin were 9.7%, 27.4%, 8.9%, 43%, 17% and 28.2%, respectively. All enterococci were susceptible to linezolid.

Anti-Bacterial Agents↗
PubMed2001

Flow cytometric analysis of spontaneous and dexamethasone-induced apoptosis in thymocytes from severely malnourished rats.

Severe malnutrition is widely distributed throughout the world, showing a high prevalence in developing countries. Experimental animal models have been useful to study the effects of malnutrition at different levels and ages. Apoptosis is a well recognised process of cell death occurring under several physiological and pathological conditions. It represents the principal mechanism involved in cell selection in the thymus. Thymocyte apoptosis induction by dexamethasone is one of the best characterised experimental models of programmed cell death. The aim of the present study was to determine whether severe malnutrition increased spontaneous and/or dexamethasone-induced apoptosis in vivo in thymocytes of experimentally malnourished rats during lactation. Thymocytes were obtained from malnourished rats at weaning (21d of age). Apoptosis frequency was estimated by the terminal transferase-mediated dUTP nick end labelling assay. Spontaneous apoptosis was 1.9 (sd 1.0) % in well nourished rats in contrast to 13.3 (sd 3.8) % in malnourished animals; this is seven times greater (P<0.001). Interestingly, the frequency of dexamethasone-induced apoptosis was similar in both groups of animals (47.9 (sd 10.1) % in well nourished rats and 53.8 (sd 8.0) % in malnourished rats). The results obtained in the present study indicate that malnutrition is associated with a significant increase of spontaneously apoptotic cells. In addition, the data showed that the fraction of thymocytes susceptible to dexamethasone-induced apoptosis was similar in well nourished and malnourished animals. The greater levels of spontaneously apoptotic cells associated with malnutrition could be related to alterations of the microenvironment of the thymus and/or to an obstruction of early thymocyte maturation.

Animals↗
PubMed1999

[Human diphyllobothriasis by Diphyllobothrium pacificum. A new case in Antofagasta, Chile].

We report a 26 years old asymptomatic female that expelled spontaneously a 39 proglottid strobila. The taxonomic study of proglottids and eggs found in the stool examination concluded that the patient was infected by Diphyllobothrium pacificum. This infection was probably acquired by the ingestion of raw fish (Sciaena deliciosa) with lemon in a traditional plate called "cebiche". She was treated with a single dose of praziquantel in a dose of 10 mg/kg body weight. After 24 h of treatment there were no scolices on feces. The patient did not have anemia. All eight family members studied, did not have the infection. A follow up stool examination three months later remained negative.

Adult↗
PubMed1998

[Does the subdural space exist?].

A potential space between the dura mater and the arachnoides is thought to exist, occupied by a serous fluid and called the subdural space. Recent studies may change this classical concept, however. The dura-arachnoid complex from the epidural to the arachnoid space is formed by morphologically distinct layers: the dura mater, the subdural compartment and the arachnoid mater, which are made up of different cell types. The dura mater consists of greater and lesser laminae formed mainly of collagen fibers aligned differently. The subdural compartment is formed by a number of so-called "neurothelial cells", which are in close contact with the inner dural layers. These cells are flat and have long interlaced branches. The arachnoides are made of cells grouped in three different layers. The outer layer is the "barrier arachnoid layer". Located just inside the anterior cell plane, this layer is made of less flattened cells that form an epithelial-type tissue, with complex cell-cell junctures surrounded by collagen fibers. The middle layer is the reticular arachnoid, composed of irregularly interlaced cells alternating with collagen fibers and intercellular gaps of varying sizes. The innermost layer, the trabecular arachnoid, is in direct contact with the subarachnoid space. The cells of this layer form strands that contribute to the weblike pattern found in the subarachnoid space. Recently, special techniques for fixing and preparing samples, preserving in situ the anatomical relations between the arachnoides and the dura mater, have allowed us to examine the normal configuration of the subdural space. All samples examined revealed the presence of a cellular plane between the dura mater and the arachnoides, with no evidence of the classically described space. The zone of least resistance in the dura-arachnoid complex was the subdural compartment, which could be torn mainly along intercellular spaces, though cell rupture was also observed, affecting the cytoplasmic membranes of adjacent cells. The subdural space is opened by tearing the subdural compartment between neurothelial cells alongside the collagen fibers of the dura mater. Such a tear can be caused mechanically by injecting air or contrast media, which exert pressure on a laminar structure that tends to separate because it is weaker than neighboring ones.

Animals↗
PubMed1997

Analysis of mitomycin C-induced micronuclei in lymphocytes from malnourished infected children.

The purpose of this study was to determine if peripheral blood lymphocytes from malnourished children with gastrointestinal or respiratory bacterial infection show increased frequencies of Mitomycin C (MMC)-induced micronuclei as compared to well-nourished, infected children. The results indicate that cells from malnourished, infected children had greater chromosome damage. This may indicate that such children would be more susceptible to environmental damage and malignant transformation. Micronucleus frequencies were analyzed in binucleate cells produced by the cytokinesis block method; the overall micronucleus frequency was significantly higher in binucleate cells from malnourished, infected children. The mean micronucleus frequency in MMC-free cultures was 4.3/1000 in malnourished infected children and 1.0/1000 in well-nourished infected children. In MMC-exposed cultures the mean induced micronucleus frequency was 32.6 +/- 6.1 vs. 12.9 +/- 2.3; 68.6 +/- 12.1 vs. 21.0 +/- 5.1, and 88.1 +/- 16.2 vs. 41.7 +/- 5.0 for malnourished and well-nourished children at 20, 40, and 60 ng/ml MMC, respectively. The number of binucleated cells with more than one micronucleus was also higher in malnourished, infected children at all doses tested, including cells with two micronuclei in MMC-free cultures from malnourished, infected children. This increase was not found in peripheral blood lymphocytes from well-nourished infected children.

Antibiotics, Antineoplastic↗
PubMed1995

Assessment of DNA damage in leukocytes from infected and malnourished children by single cell gel electrophoresis/comet assay.

The alkaline single cell gel (SCG) assay is a sensitive electrophoretic technique for detecting the presence of DNA single strand breaks and alkali-labile damage in individual cells. This technique was used to assess and compare the level of DNA damage in peripheral blood leukocytes/lymphocytes from well-nourished children with infection, well-nourished children with infection and under drug treatment, and from malnourished infected children with and without previous drug treatment. The present study shows that severe infection is associated with a significant increase in DNA damage. The average migration length was five times greater in severely infected well-nourished children compared to that found in healthy, well-nourished children. The results obtained in this study indicate that malnutrition is another factor associated with an increase in DNA migration. The average tail length for malnourished, severely infected children was twice as great as that obtained for cells from well-nourished, severely infected children. We also detected a variable increase in DNA migration associated with treatment for severe infection. Nevertheless, the excessive heterogeneity, the concurrent number of drugs used and the limited size of the treated population precludes an accurate assessment of which drugs were involved in the increase in DNA damage. Further studies will be necessary involving a large number of patients to address the relation between levels of DNA damage and specific kinds of infection, various drug treatments, and the type and severity of malnutrition. The increased level of DNA damage in severely infected and malnourished children could be related to negative effects such as a deficient immune response resulting in an increased susceptibility to malignant transformation.

Child↗
PubMed1995

Intrapartum prophylaxis with ceftriaxone decreases rates of bacterial colonization and early-onset infection in newborns.

Because of high rates of neonatal gram-negative sepsis in many Latin American countries, we prospectively enrolled 784 high-risk pregnant women in a study designed to evaluate the effect of a single 1-g dose of ceftriaxone (n = 390) vs. that of no antibiotic prophylaxis (n = 394) on oral, rectal, and umbilical colonization and fatality rates among newborn infants. The mean ceftriaxone concentration in cord blood samples was 26 microgram/mL (range, 9-40 microgram/mL). Compared with infants of untreated mothers, children born to women who were given ceftriaxone were colonized at a lesser rate by gram-negative bacilli (54% vs. 35%; P < .001) and by group B streptococci (54% vs. 21%; P = .03) and endured significantly fewer sepsis-like illnesses in the first 5 days of life (8.1% vs. 3.1%; P = .004). There was also a tendency for them to have fewer episodes of culture-proven early-onset sepsis (2.8% vs. 0.5%; P = .06). Sepsis-related case-fatality rates (0.8% and 0.3%, respectively) were not significantly different. Although intrapartum administration of a single dose of ceftriaxone to high-risk mothers could be a safe and potentially useful strategy for reducing early-onset neonatal infections, additional information is required before this approach can be recommended for routine prophylaxis.

Bacterial Infections↗
PubMed1995

[Pseudosarcomatous tumor of the bladder].

Pseudosarcomatous tumour of the bladder is a benign neoforming process of uncommon occurrence, consisting in a fibroblastic proliferation originated in the vesical wall and the perivesical fat, with unknown etiology, that given its cellular pleomorphism and the infiltrative nature of the injury can be incorrectly diagnosed as a sarcoma. This paper presents one case of pseudosarcomatous tumour of the bladder in a 9 year-old child, with no history of local traumatism or previous surgery, consisting in a tumoration affecting the vesical wall associated with a significant perivesical fibrosis with extension towards the area of the iliac veasels. Microscopically, the injury shows proliferation of spindle cells, arranged in a myxoid stroma with a prominent vascular net. No cytologic atypia is demonstrated or increase in the number of mitosis. The immunohistochemical study shows features of myofibroblasts in the proliferant cell. A review of the literature is made on 40 cases of inflammatory pseudosarcoma, evaluating the clinical characteristics, morphologic findings and treatment involved, as well as the postoperative evolution of the patient.

Child↗
PubMed1979

[Total colonic aganglionism (author's transl)].

Total colonic is the most frequent form of extensive aganglionism. Diagnosis is difficult, but it must be taken in mind whenever either muscoviscidosis or ileal atresia are considered. Nine cases out of a series of 319 aganglionisms seen between 1957 and 1977 are reported. Ileostomy can be lifesaving but Duhamel-Lester Martin technique must be elected as a definitive treatment. The modification proposed by the authors, carried out in three cases, can be performed as a first-choice operation in the newborn. The long term results in these three cases are compared to those of other techniques. A general review of the problem is made.

Appendicitis↗
PubMed1978

[Ileocaecal valve incompetence. A new syndrome (author's transl)].

Out of series of 237 colonic aganglionisms (1965--1977) 32 cases (13%) showed a clincial, radiological and manometric syndrome of "incompetent ileocaecal valve". Symptoms were vomiting, constipation with bouts of diarrhea, incomplete intestinal obstruction and failure to thrive. Sixteen cases were under P-3 weight percentiles. Initial diagnosis were aganglionism (10 cases), hiatal hernia (4 cases) and N.E.C. (1 case). Seventeen patients were explored through an iliac incision in the first three months of life. Ileocaecal continence was minimal (less than 25 cm. of water pressure). Ilocaecoplication was performed and completed with internal sphincterectomy (10 cases), colostomy (1 case) and caecostomy (3 cases). This new syndrome has been experimentally studied, but its etiology remains obscure. It introduces a bad prognostic component in aganglionism. Ileocaecoplication, a very simple operation, can be a lifesaving procedure.

Humans↗
PubMedDate not supplied

Cysteamine protection of SCEs induced by UV and fluorescent light.

CHO cells were grown for 36 h in the presence of BUDR. 12 h before harvesting, the cells were irradiated with UV or with fluorescent (FL) light. Part of the cultures were treated with cysteamine (Cys) during irradiation. Metaphase spreads were stained by the Hoechst-plus-Giemsa method, and the frequency of SCEs per chromosome was determined in second-mitosis cells. The basal frequency of SCEs (1.07 +/- 0.073) was not increased by Cys treatment (1.15 +/- 0.048). On the other hand, UV and FL induced a 3-4-fold increase in the frequency of exchanges (4.18 +/- 0.2 and 3.32 +/- 0.12 resp.). Cys, when present during irradiation, markedly reduced the frequency of UV- and FL-induced SCEs (2.7 +/- 0.14 and 2.29 +/- 0.11 resp.). It is assumed that Cys prevents the formation of radiation-induced breakages in the BUDR-substituted DNA. The residual increase over the basal levels of SCEs which remains after the treatment with Cys may be due to the persistence of some open breaks, to the presence of protein-DNA crosslinking, or to the combined action of both types of lesion.

Animals↗
PubMedDate not supplied

[Low ano-rectal malformations (author's transl)].

This work includes 61 cases of low anal atresias, 42 were female and 19 male. All of them were treated with "cutback" technique with a follow up longer than two years. Results are classified in good, regular and poor, depending on the continence, stenosis, mega-rectum and enchopresis, and were 90 per cent of good results, 8 per cent regular and 2 per cent poor. Authors recommend this technique as a choice proceding in this kind of low atresias.

Anal Canal↗